A number of prior art devices exist for the purpose of extracting a tooth or otherwise holding or clamping teeth during dental and orthodontic procedures. For instruments such as dental forceps, the amount of force applied to a particular tooth is determined by the force which the dentist exerts on the forceps. For dental or orthodontic clamps, the amount of force exerted on a particular tooth is determined by the force of the spring or resilient member used in conjunction with the clamp.
One representative example of medical forceps includes U.S. Pat. No. 4,727,876 to Porat, et al. which discloses plastic gripping members mounted to a pair of handles. The proximal ends of the handles are connected to one another resulting in a biasing force which keeps the forceps in a normally open position.
U.S. Pat. No. 4,001,940 to Cusato discloses an elastic positioner apparatus for orthodontic procedures. This apparatus is also characterized by a pair of handle members connected at their proximal ends resulting in a biasing force which keeps the handle members in a normally open position. The apparatus further includes a cam block which enables the jaws of the handle members to be maintained at a set distance from one another. In an alternative embodiment, Cusato discloses a spring carried by a pin member which urges the jaw tips to a closed position.
U.S. Pat. No. 2,267,836 to Parkin; U.S. Pat. No. 2,645,013 to Mathison; and U.S. Pat. No. 3,191,304 to Mattern are each representative of dental clamps or retainers which are characterized by a pair of opposed handles which are forced to a normally closed position by a spring.
U.S. Pat. No. 3,507,043 to Rubin; U.S. Pat. No. 4,217,686 to Dragan; and U.S. Pat. No. 4,310,305 to Frajdenrajch are representative of orthodontic pliers which also incorporate a spring or biasing member to place the pliers in a normally closed position.
While the foregoing inventions are suitable for their intended purposes, none of them are especially adapted for the removal or extraction of a tooth wherein a preselected and adjustable amount of force may be placed on the tooth by the device in order to remove the tooth.